Snap-on cartridge-needle unit



April 1, 1958 D. M. AsHKENAz ETAL SNAP-0N CARTRIDGE-NEEDLE UNIT FiledJune 17, 195'? ATTORNEY United States Patent() SNAP-ON CARTRIDGE-NEEDLEUNIT David M. Ashkenaz, Bala Cynwyd, Pa., and Marston L. Hamlin,Lynbroolr, N. Y., assignors to American Home Products Corporation, NewYork, N. Y., a corporation of Delaware Application June 17, 1957, SerialNo. 665,929

7 Claims. (Cl. 12S-41E) ment simultaneously causes the needle topenetrate the closure and seats the needle firmly in a ferrule securedto the cartridge.

Various tonus of cartridge-needle units have been proposed in which anvinjection needle is brought into communication with the interior of thecartridge by a simple relative linear movement. In these units needlehubs and cartridge ferrules of both metal and plastic have beenproposed. All of these, as far as we know and in contrast to those unitswhich comprise a screw-threaded connection, suier from the disadvantageof an insulliciently secure seat for the needle when in communicationwith the interior of the cartridge.

It is an object of the present invention to provide a cartridge-needleunit of the kind described in which a simple longitudinal movement ofthe needle simultaneously causes it to penetrate the cartridge closureand seats it firmly on the cartridge without wobble.

It is a further object to provide such a unit having a needle fixedlymounted in a hub provided with an external skirt surrounding a cartridgeferrule and an internal male cone mating with a tapered female recess ina cartridge ferrule.

It is an additional object to provide such a unit in which the needlehub may be fabricated of synthetic plastic.

Other objects and advantages of our invention will be apparent from thefollowing description which, with the drawing, is intended to beillustrative only and not to limit our invention, the scope of which isdefined in the appended claims.

In the drawing:

Fig. 1 is va longitudinal section of a cartridge-needle unit accordingto one embodiment of our invention;

Fig. 2 is an enlarged section of a portion of a slightly modified formof the invention;

Fig. 3 shows our unit in place in a syringe body;

Fig. 4 illustrates our invention, partly in section, applied to adisposable syringe; and

Fig. 5 is a perspective view, partly in section, of a modified form ofneedle hub according to our invention.

In the drawing a tube 1 containing an injectable drug 2 is closed at itsproximal end by a slideable plunger 3 provided with a threaded stud 4adapted to engage a push rod 5 having a thumb piece 6. The distal end oftube 1 is closed by a penetrable closure which may be a at disc 7 or aflanged stopper 8. The closure is seated on and compressed against tubeange 9 by means of a crimped skirt 10 integral with ferrule 11.Alternatively the crimp- 2,828,743 Patented Apr. 1 1958 ing means may bea separate flanged collar 12 as show in Fig. 2.

Fei-rule 11 has a central bore 13 which is cylindrical in its proximalpart but has the form of hollow inverted circular cone 14 in its distalpart. The exterior of the ferrule is provided in its proximal part witha male thread 15 adapted to mate with the female thread 16 in'the distalend of a syringe 17 as shown in Fig. 3. l i An alternative form offerrule 111 is shown in Fig. 2. This diers from ferrule 11 (Fig. l) inhaving a llange 18 to furnish a bearing for crimping collarr12, and inlacking an exterior thread such as 15. This type of fer- .rule issuitable for use in syringes in vwhich the cartridge is secured againstlongitudinal movement by means other than a threaded connection. Y l Ator near the distal end our ferrule is preferably provided with a fillet19 serving to aid in securing an injection needle 20 in a desiredposition as described below. The double-pointed injection needle 20 isfixedly mounted in the axis of a hub 21 with its proximal point 22projecting from hub 21 as shown in Figs.,1. and`v2. The hub is made ofan elastic or lspringy material; this is preferably a synthetic plastic,but alternatively may be a metal of suitable characteristics. Proximallyhub 21 has an internal bore l23 in which is located a solid in-v vertedcircular cone 24 adapted to mate with and form a taper joint with hollow`cone 14. Bore 23 is defined by a resilient cylindrical exterior skirt25 and at both its proximal and distal ends is provided withcircumferential grooves 26 and 27 adapted to mate with llet 19.

When `assembled for packaging, hub `Z1 is slipped over ferrule 11 farenough so that groove 26 is sprungover fillet 19 as permitted by theelasticity of the hub material.- This engagement of groove and filletprevents accidental displacement of the needle prior to preparation ofthe syringe for injection.

Before use for injection, the hub is moved' further proximally withrelation to the ferrule so that cone`24 seats in conical bore 14,forming a firm taper joint. vThe dimensions of hub and ferrule are sochosen vthat when cone 24 is seated in conical bore 14, needle point 22pene-I trates closure 7 or 8 and simultaneously groove 27 snaps overfillet 19. In this position the taper joint 14-24 assures a rigidpositioning of the needle and the engagement of groove 27 with fillet 19prevents accidental withdrawal of the needle.

In packaged form needle 20 is provided witha sheath 28 of rubber orsimilar flexible elastomer. This sheath is closed at its distal end 29and at its proximal end 30 fits snugly over hub 21 and a portion offerrule 11. The main function of sheath 28 is to maintain sterility ofneedle land hub prior to use.

In assembly, the cartridge-needle unit is sterilized by any suitableconventional method.

To give an injection with the units illustrated in Figs. 1-3, the userinserts and secures the unit in a syringe (as in Fig. 3 for example),grips `sheath 28 with his fingers opposite hub 21 and presses the hubtowards the syringe. This forces cone 24 to seat itself in tapered bore14, simultaneously snapping circular groove 27 over fillet 19 andcausing point 22 of needle 20 to penetrate closure 7 or 8 as the casemay be. A firm seat is thus provided for needle 20 when it is incommunication with the contents 2 of tube 1.

Up to this point there is no need for the user to take precautionsagainst contamination of the needle since it is still protected by thesheath. It is thus possible for a number of syringes to be prepared andlaid out at one time, e. g. when multiple injections are to be given toone or a series of patients.

When ready, the user slips off the sheath and makes the injection.

Application of our invention to a disposable or one shot syringe isillustrated in Fig. 4. l'n such syringes the drug-containing tube 201itself serves as the syringe body. It is provided with a finger lange31, and push rod 2%5 doubles asa protective needle cover. The push rodhas an outside diameter sutiiciently small to pass through the bore oftube 201 and has an internal bore 32 suiiiciently large to accommodateneedle and sheath. lt is provided at its proximal end externally with aiiange 206, serving as althumb piece, and internally with a femalethread 236 mating with male thread 15, and serving to retain the rod inposition until the syringe is used. At its distal end rod 205 isprovided with a female thread 32 adapted to mate with the thread on stud4. Y

fThe user of the syringe of Fig. 4 first removes rod 205,from ferrule11, aixes it byrthread 32 and stud ft to plunger 3 and manipulates hub24, as described in connection with Figs. 1-3, to cause the proximal end22 of needle 20 to penetrate the cartridge closure 7. Then, immediatelybefore injection, he slips off sheath 28 to expose the sterile needle.

Hub 24 is advantageously made of a synthetic polymer having a moderatedegree of elasticity, such as will permit grooves 26 and 27 to pass overand engage ferrule 19,'but having suicient body to provide a firm mountfor the needle when taper joint 14--24 is engaged. Numerous resinsmeeting these requirements are available commercially, one such beingrigid polyethylene produced commercially'by several manufacturers. Ifmore resiliency is required, as for example in a metal hub, the skirt125 of a modified hub 121 may be provided with a series of longitudinalslots 33, as shown in Fig. 5.

From the above description it will be seen that we have provided acartridge-needle unit having a hollow needle firmly mounted out ofcontact with the cartridge contents but ladapted by a simple linearmovement to be brought into communication with the cartridge contents,in which position it is held rigidly and without wobble. The unit isadapted to be packaged and distributed with the needle and hub insterile condition and protected against contamination; accidentalpenetration of the cartridge closure by the needle is eliminated.

In the specification and claims distal is used to denote a position ordirection towards the needle andV proximal a position or directiontowards the plunger.

We claim:

1. A cartridge-needle unit comprising a ferrule crimped around the angedend of a drug-containing tube,` a penetrable closure secured to theanged end of the tube by i.

end with a solid inverted cylindrical cone adapted to mate with thehollow cone of the ferrule and being provided with a resilient skirtsurrounding the solid cone and adapted to tit friction-tight over thedistal end of the terrule, the needle hub being engaged with the ferrulea suicient distance to bring a point of the needle close to but notpenetrating the cartridge closure, the dimensions of ferrule and hubbeing so chosen that when the said solid cone is seated in said hollowcone by longitudinal movement of the hub with respect to the ferrule,the needle penetrates the tube closure.

2. A cartridge-needle unit according to claim l in which the ferrule isprovided with a iillet near its distal end and the skirt of the hub isprovided with an internal circular groove adapted to mate with thefillet.

3. A cartridge-needle unit according to claim l in which the ferrule isprovided with a fillet near its distal end and the skirt of the hub isprovided with two internal circular grooves adapted to mate with thefillet, the grooves being spaced longitudinally so that one engages thellet when the needle is not in communication with the contents of thetube and one engages the fillet when the needle is in communication withthe contents ofthe tube and the solid cone of the hub is seated in thehollow cone of the ferrule.

4. A cartridge-needle unit according to claim 1 having an elastomericsheath, closed at its distal end, surrounding the needle and at itsproximal end surrounding the needle hub friction-tight.

5. A cartridge adapted to be packaged with an injection needle mountedthereon, comprising a tube having a flanged end, a penetrable closure onthe flanged end and a ferrule crimped around the lianged end andsecuring the closure to the tube, said ferrule extending distally fromthe tube, having an axial bore in the form of an inverted hollowcircular cone, and provided with a fillet near its distal end.

6. In combination a syringe body having a barrel adapted to receive acartridge-needle unit, means to secure a cartridge-needle unit againstlongitudinal movement, and a cartridge-needle unit as dened in claim l.

7. A cartridge-needle unit as defined in claim l, in which the tube isprovided at its proximal end with an exterior flange and which is closed'at its proximal end by a slideable plunger having a threadedconnection, in combination with a rigid hollow needle cover adapted tobe removably mounted on the ferrule and surrounding the needle, theneedle cover having an outside diameter less than the bore of the tubeand having at it-sdistal end a threaded connection adapted to mate withthe threaded connection of the slideable plunger, whereby the needlecover may serve as a push rod and the combination constitute adisposable syringe.

Hein' June 5, 1934 Dann Mar. 9, 1954

